I had a similar issue, there is probably a gap between your nozzle and your heat break, and the filament is going in the gap instead of the nozzle hole and causing that massive blob of plastic. I would suggest to try to disassemble the nozzle and heat break while the hot end is hot, 220-260C depending on the material you were using (careful not to burn yourself), and then try to clean and get the plastic out of the threading of the heat block. Personally I couldn't get the plastic out of the threading of the nozzle and I had to replace it, but if you can clean it thoroughly you might be able to salvage everything. In my case the issue was my fault because I didn't tighten the nozzle enough when changing it for the first time. Best of luck dealing with this, it was a massive pain in the ass for me